Previously, ladders have been made with very wide materials such as lumber or aluminum. Ladders are difficult to store indoors due to their width. Typically a ladder is 3-6 inches in width which makes it difficult to store inside a home. For example, such a ladder is difficult to fit behind a door or similar tight space. In addition, many ladders and step stools have more than one frame member and when folded the frame members add to the thickness of the folded ladder. For example, the frame members may be made of 4" wide lumber. When folded the total width are typically more than one width of the frame, such that the total width may be 5-8".
A problem associated with these ladders is that they are difficult to store. Typically, the ladders can not be stored easily within the house or in the areas, such as a kitchen, where the ladder would be used most often. In a kitchen, for example, ladders are useful for gaining access to supplies and dishes on high shelves. Another problem with these ladders is that they are heavy and so are not easily moved within the house. As a result, most ladders are stored in the garage of a typical household.
The American National Standards Institute (ANSI) has standards which cover ladders. The standards are a series of tests with acceptable ranges. It is very advantageous to have any ladder comply with the standards. If a ladder complies with all the ANSI standards, then a retailer feels more comfortable in offering the product to their customers. The standard tests were formulated on the heavy ladders made of substantial material, such as the 4" lumber. When designing a ladder having less weight and which can be used indoors, meeting the standards is more of a challenge. Currently, most ladders that are designed for use in a house do not meet any or all of the ANSI standards for ladders.
A constant goal of manufacturers is to build a product which is easy to manufacture. If one or more steps can be eliminated without compromising the quality of the product, the manufacturer is able to decrease the cost of manufacture and either increase the profit margins or pass the savings onto the consumer. A better process is to manufacture a product having increased quality in less steps. Another goal of manufacturers is to make a product which is aesthetically pleasing. In other words, a ladder that looks better also appears to be of higher quality to the consumer. Still another constant goal for making a ladder for indoor use is to make a lighter ladder which is easier to handle.
The first frame member includes at least one cross member for supporting each of the one or more steps of the ladder. The cross members also provide a pivot axis about which the step rotated when folded or unfolded. In the past, each step of the ladder included a pair circular openings or a cylindrical opening through which the cross member was threaded. The opening fully surrounded the cross member. During manufacture, the cross members had to be threaded into the opening or openings of the step and then the combined cross member and step had to be attached to the first frame member. Alternatively, in a design which uses pivoting steps or treads, one or more members which serve as an axis of rotation must be attached to each step before attaching the step to the first frame. Attaching a combination step and pivot member to a frame is more difficult than merely attaching a cross member to a frame during manufacture.
There is a need for a lightweight ladder for indoor use that is aesthetically pleasing to the eye and which meets all the standards set forth by ANSI. There is also a need for a higher quality ladder. There is a further need for a manufacturing method which can eliminate or ease the steps involved so that the ladder can be manufactured with greater ease. There is also a need for a manufacturing method which allows the cross members to be attached to the ladder without having to first combine the cross member and the step.